This invention relates to a device for introducing a catheter into the human body. More specifically, this invention relates to a Ventricular Catheter Introducer (VCI) which includes a cannula, a stylet disposed within the cannula, and means for holding a catheter in close proximity to the cannula and stylet so that the tip of the catheter will be positioned near the tip of the cannula after insertion thereof. In the disclosed embodiment, the stylet may be releasably locked in position within the cannula. The disclosed design allows the user to sample fluid from the insertion site and to inject materials into the insertion site without the need to re-introduce a needle therein.
VCI devices are generally known in the art for introducing catheters into certain areas within the human body such as into a ventricle of the brain, for example. Catheters are generally manufactured with a flexible material having an opened end and a closed end. The closed end of the catheter is generally intended to be inserted into the body and is provided with a plurality of holes within the sidewalls thereof to allow fluid to pass. The opened end of the catheter is most often connected to an apparatus such as a valve or a pump. The interior of such a catheter is generally inaccessible, thereby preventing the use of a simple stylet for providing some rigidity to the catheter structure when the catheter is inserted into the desired area of the body.
Various VCI devices are known in the art which provide a cannula having a stylet releasably disposed therein in such a manner that the free end of the stylet protrudes from the free end of the cannula. The protruding stylet forms a shoulder with the free end of the cannula. The protruding end of the stylet can be inserted into one of the pores or holes in the side walls of the catheter so that the catheter will abut against the aforementioned shoulder thereby connecting the closed end of the catheter with the free end of the introducer. The catheter may then be placed within the body at the desired site by inserting the introducer/catheter combination therein. After insertion, the closed end of the catheter is freed from the stylet by retracting the stylet into the cannula. If desired, the stylet and the cannula can then be removed from the insertion site while leaving the catheter in position.
Prior art introducers generally are limited in several aspects. For example, in order to perform an injection near the inserted end region of the catheter, it has been necessary to reintroduce a needle into the insertion area. Re-introduction of a needle is generally undesirable because of the potential danger, especially when carried out in the brain. Further, it is difficult to determine whether the injection has been made in the required position, i.e. near the inserted end of the catheter. Prior art introducers generally include no means for retaining the inserted stylet in its proper position within the cannula during insertion of the introducer and the catheter. Consequently, the stylet may retract into the cannula and be unintentionally disconnected from the catheter, requiring that the operation be restarted. Additionally, prior art introducers contain no means by which the user can sample the fluid at the insertion site in order to determine whether the catheter has been positioned at the desired drainage area. In the insertion of a ventricular catheter, for example, the detection of cerebrospinal fluid would indicate that the catheter has been inserted into the desired position, i.e. within the ventricle of the brain.
The present invention overcomes the above-discussed limitations of the prior art introducers by providing a catheter introducer including a tubular cannula, a stylet removably retained within the cannula, and means for holding a catheter in close proximity to the cannula and stylet. The VCI of the present invention allows a user to introduce and properly position a catheter within the body. Means are provided to releasably lock the stylet within the cannula and to thereby prevent the unintentional retraction of the stylet into the cannula during insertion of the introducer and catheter into the human body. Additionally, the cannula is provided with a body portion which is dimensioned to engage the end of a syringe. In this manner, injections may be made without the need to re-introduce a needle into the insertion site. In this arrangement of parts, the user can be certain that the injection is placed at or near the end of the inserted catheter. Discharge means are also provided which allow body fluids to pass through the introducer as an indication that the desired insertion area has been reached.
Accordingly, it is an object of the present invention to provide a catheter introducer including a cannula, a stylet disposed within the cannula and means for holding a catheter in close proximity t the cannula and stylet;
It is another object of the present invention to provide the catheter introducer wherein the stylet may be releasably locked within the cannula to prevent the unintentional retraction of the stylet into the cannula during insertion of the catheter into the human body;
It is still another object of the present invention to provide a catheter introducer which can engage a syringe to thereby allow the placement of an injection near the tip of the inserted catheter;
It is still another object of the present invention to provide a catheter introducer having means for allowing body fluids to pass therethrough to indicate that a desired insertion area has been reached.